Objective

To assess the effects of hemodilution on clinical outcomes in patients with acute ischemic stroke.

Methods

We searched the Cochrane Stroke Group Trials Register (February 2014), the Cochrane Central Register of Controlled Trials (Issue 1, 2014), MEDLINE (January 2008 to October 2013), and EMBASE (January 2008 to October 2013). We also searched trials registers, scanned reference lists, and contacted authors. We included randomized trials of hemodilution treatment in acute ischemic stroke, started within 72 hours of symptom onset, and which reported clinical outcomes. Two authors assessed trial quality and 1 author extracted the data.1

Main Results

We found 21 trials involving 4174 participants matching our selection criteria. Nine trials used a combination of venesection and plasma volume expander. Twelve trials used plasma volume expander alone. The plasma volume expander was plasma alone in 1 trial, dextran 40 in 12 trials, hydroxyethyl starch in 5 trials, and albumin in 3 trials. Two trials tested hemodilution in combination with another therapy. Evaluation was blinded in 14 trials. Five trials probably also included some participants with intracerebral hemorrhage. Hemodilution did not significantly reduce death within the first 4 weeks (risk ratio, 1.10; 95% confidence interval, 0.90–1.34; Figure). Similarly, hemodilution did not influence death within 3 to 6 months (risk ratio, 1.05; 95% confidence interval, 0.93–1.20) or death and dependency or institutionalization (risk ratio, 0.96; 95% confidence interval, 0.85–1.07). The results were similar in confounded and unconfounded trials, and in trials of isovolemic and hypervolemic hemodilution. No statistically significant benefits were documented for any particular type of hemodiluting agents, but the statistical power to detect effects of hydroxyethyl starch was weak. Six trials reported venous thromboembolic events. There was a trend toward reduction in deep venous thrombosis, pulmonary embolism, or both at 3 to 6 months (risk ratio, 0.68; 95% confidence interval, 0.37–1.24). There was no statistically significant increased risk of serious cardiac events among hemodiluted patients.

Comparison of hemodilution, all types, vs control, on the outcome of death or dependent/institutionalized at 3 to 6 months. CI indicates confidence interval.

Conclusions

We did not find clear evidence of benefit of hemodilution therapy for acute ischemic stroke on clinical outcomes.

This article is based on a Cochrane Review published in The Cochrane Library 2014, Issue 8 (see www.thecochranelibrary.com] for information). Cochrane Reviews are regularly updated as new evidence emerges and in response to feedback, and The Cochrane Library should be consulted for the most recent version of the review.

Sources of Funding

Dr Chang was supported by the Clinical and Translational Science Award program, previously through the National Center for Research Resources grant 1UL1RR025011, and now by the National Center for Advancing Translational Sciences grant 9U54TR000021, as well as by the National Institutes of Health (NIH) T32 GM008692 and the National Heart Lung and Blood Institute Fellowship F30HL112491. Dr Jensen was supported by NIH grant 1K08NS079622-01A1.